The Crimean War (1853-1856) was a significant military conflict fought primarily on the Crimean Peninsula, involving Russia against an alliance of the Ottoman Empire, France, Britain, and Sardinia, stemming from disputes over the rights of Christian minorities in the Holy Land, then part of the Ottoman Empire. It exposed logistical and strategic shortcomings in military operations, led to advancements in battlefield medicine and nursing, particularly through Florence Nightingale's efforts, and marked a shift towards modern warfare with the use of railways and telegraphs.